Quantification of Pentosidine in Avian Plasma

Abstract

Sustained elevated plasma glucose concentrations, such as occurs in diabetes, leads to the non-enzymatic binding of glucose to serum albumin forming glycated albumin. Subsequent chemical rearrangement leads to the formation of irreversible Advanced Glycation Endproducts (AGEs). These AGEs can cause severe complications of diabetes such as microvascular and renal damage. It has been demonstrated that birds, as a normal aspect of their physiology, have plasma glucose concentrations of 350 mg/dL or higher. This concentration is about three times higher than that of mammals. This suggests that birds may have higher concentrations of AGEs in their plasma compared to mammals. However, we suggest that there is not a positive relationship between pentosidine and glucose levels in avian plasma, which would explain the absence of hyperglycemic complications. Pentosidine is a well-characterized AGE, stable under acid hydrolysis and has a lysine and arginine fluorescent cross link, allowing it to be easily detectable at low concentrations using High Performance Liquid Chromatography. Because of the amino groups available on pentosidine, we found that it could be easily detected using the Ninhydrin assay. Our results revealed an average pentosidine concentration of 0.032 pmol/ul and average glucose concentration of 390 pmol/ul in avian plasma.